1. Field of the Invention
This invention relates to a device for mounting column switches such as a turn signal switch, a wiper switch, and the like on a base board in a vehicle.
2. Description of the Prior Art
In the prior art, these kinds of column switches have been fixed by screws directly on the handle shaft tube or on the under surface of the column base board. Such a method for fixing switches by means of screws has made complex the work of mounting vehicle column switches and increased the man-hours required for installation. At the same time, there occurred variations in the mounting conditions of such column switches according to the workers' skill and it has been difficult to produce stable vehicle column switches with high quality.
There is available another mounting method for vehicle column switches, where U-shaped depressions are formed in the base board, wherein the column switches for vehicles such as a turn signal switch and a wiper switch are formed into a housing shape, and are fitted in the U-shaped depressions. The housing-shaped column switch for vehicles is provided with an engaging arm, which serves to engage the column switch with the U-shaped depression in the base board and fix it there through a single push action. In this method, an operating lever for the vehicle column switches is operated to control the functions of each switch. But repetitive use of the operating lever made the housing-shaped column switches unstable in the U-shaped depressions, and in the worst case, caused them to fall off from the depressions. Furthermore, this method had the problem that the engaging arm provided at the side surface of said column switch is easy to break, and made it impossible to fix said vehicle column switch to the bottom of the base board.
In order to fit in and securely engage the vehicle column switches with the U-shaped depressions in the base board, it is necessary to provide an engaging projection at each internal wall of the U-shaped depression and also at least one engaging arm on the side surface of the housing-shaped column switch for vehicles, which has complicated the molding process for the product and made the product very expensive.